Historical Research Review


Hereditary Sensory Neuropathy Type I (HSN I) is a rare genetic disorder characterized by the loss of sensation, especially in the feet and legs, and progressing to the hands and forearms. The loss of sensation is caused by abnormal function of the autonomic nervous system, which controls responses to pain and temperature as well as other involuntary or automatic body processes.

The most common type of inherited sensory neuropathy is Charcot-Marie-Tooth (CMT) disease. Some texts do not differentiate between this more common neuropathy and any other sensory neuropathy. Doctors who are not specialists in this area may diagnose someone with HSN I as having CMT.

In 1922 E. P. Hicks published an article in an English medical journal describing an English family in which 10 members suffered from perforating ulcers of the feet, shooting pains and deafness. In 1951 D. Denny-Brown published a follow up report on one of the members of this family, identifying the disease as “hereditary sensory radicular neuropathy.” In 1939 Drs. Tocantines and Reimann published their first report on Harvey and Russell Deater and other members of the family. Drs. Reimann, McKechnie, and Stanisavljevic published a follow up report in 1968. Similar symptoms were noted in French-Canadian, English, and Australian families.

During these early years, neurological exams, biopsies, and nerve conduction studies were the only means of identifying the disease. There was some variation in the symptoms, including restless legs, severe sensory loss, and burning feet. Various members of the Deater family participated in studies at The National Institutes of Health during the 1970s with Dr. John Whitaker and Dr. Marinos Dalakas.

In 1986 Dr. Robert Brown drew blood from family members to begin a study at the Day Neuromuscular Lab at Massachusetts General Hospital. By 1992, Dr. Khemissa Bejaoui was involved in the research. At the turn of the 21st century the method of diagnosis changed when Dr. Garth Nicholson in Australia identified a genetic mutation causing the disease. Very soon after that Dr. Khemissa Bejaoui independently identified mutations in other patients, including those in the Deater family.

The mutations on chromosome 9 were slightly different in different families. The gene involved is a known gene, SPTLC1. Many people around the world had already been studying this gene and the enzyme associated with it. Dr. Bejaoui found that the mutations in the gene resulted in reduced enzyme activity and sphingolipid production. This discovery moved the research concerning HSN 1 much closer to the goal of identifying exactly what causes nerve destruction and ultimately, to treatment.